Within health care today administration of medicaments by inhalation for distributing dry powder medicaments directly to the airways and lungs of a user is becoming more and more popular, because it offers an efficient, fast, and user friendly delivery of the specific medication substance.
Different types of inhalers are available on the market today, such as metered dose inhalers (MDIs), nebulizers and dry powder inhalers (DPIs). MDIs use medicaments in liquid form and may use a pressurized drive gas to release a dose. Usually MDIs have a relatively low capacity for delivering an effective dose of the active substance in a single inhalation and many devices have problems with using a drive gas which is environmentally acceptable. Nebulizers are fairly big, non-portable devices. Dry powder inhalers have become more and more accepted in the medical service, because they deliver an effective dose in a single inhalation, they are reliable, often quite small in size and easy to operate for a user. Two types are common, multi-dose dry powder inhalers and single dose dry powder inhalers. Multi-dose devices have the advantage that a quantity of medicament powder, enough for a large number of doses, is stored inside the inhaler and a dose is metered from the store shortly before it is supposed to be inhaled. Single dose inhalers either require reloading after each administration or they may be loaded with a limited number of individually packaged doses, where each package is opened shortly before inhalation of the enclosed dose is supposed to take place.
Gelatin or plastic capsules and blisters made of aluminum or plastic, or laminates comprising aluminum and plastic foil are common prior art containers for metered single doses of dry powder medicaments. Typically, the user has to open the inhaler, insert at least one container into the inhaler, close it, push a button to force one or more sharp instrument(s) to penetrate a selected container, such that the dose may be accessed by streaming air when the user at leisure decides to inhale the dose. Besides a method of breaking the container open inside the inhaler and pouring out the dose in a chamber first, the most common method of opening the container is to punch one or more holes in the container itself or in a foil sealing the container. In the first case the powder is poured onto a surface inside the inhaler and made available for inhalation from there. In the second case the dose is aerosolized by inhalation air being forced through the container or the dose being shaken out of the container and immediately aerosolized by streaming air on the outside of the container.
New types of dry powder medicaments, not least for systemic treatment, have a rather short expiry date and they are generally quite sensitive to ambient conditions, especially moisture during storage and in use. Hence, the demands put on dose protection and inhaler devices in handling sensitive doses are therefore much higher than for prior art devices as used e.g. for administering traditional medicaments against respiratory disorders. For instance, prior art blister packages for dry powder medicaments, intended for inhaler use, often use a fairly thin polymeric seal, which can be easily ripped or punched open before the dose is supposed to be inhaled. Another common seal is a peelable blister such that the blister is peeled open prior to inhalation of the enclosed dose. Yet another type of prior art dose container is the capsule. Capsules are often made by gelatin, but polymers and cellulose and other materials are also used. A common problem for prior art blisters and capsules used for dry powder doses for inhalation is that the primary package does not protect sensitive substances from moisture well enough during storage and in use. Minimizing the time the primary package is exposed to the atmosphere and minimizing the time during which the dose is subjected to the ambient atmosphere after opening of the container are therefore important aspects of inhaler and dose container design.
There is a demand for an improved method and device, which will simplify loading and opening of the dose container to make the powder dose enclosed therein easily available to a user of the DPI.